Oil platforms, and other man-made offshore structures such as
breakwaters and shipwrecks, create circalittoral hard substratum in areas where it did not
exist before. The amount of substratum is probably fairly insignificant, but its position
may play a role as a staging post in promoting spread of species. Certainly artificial
structures quickly accumulate a diverse animal community (Forteath et al., 1983). This is
not so much a question of man posing a problem for CFT communities, as the other way
round.

In terms of their effect on the structures CFT species increase drag,
and accelerate corrosion (Pipe, 1981). Detail would not be appropriate here, but a better
understanding of the biology of the important species involved (Tubularia spp., Akcyonium
digitatum, Metridium senile, Pomatoceros triqueter, Balanus spp.) could perhaps help
to mitigate the problem.

Whilst CFT communities are not desired on most artificial structures,
there are some which are deliberately constructed to promote natural communities. These
are the artificial reefs, developed primarily to provide increased habitat for
fish and shellfish. An integral aspect of this is the establishment of a complex community
to provide habitat and food for the target species. An example of such a development is
the Poole Bay Project where the reef was constructed of stabilised coal-fired power
station waste (Collins et al., 1990; Jensen et al., 1994).